The present invention relates generally to decks, and more particularly, to a method of manufacturing a sacrificial limb for a deck plank.
Wood is commonly used for decks. However, the use of wood for decks presents a number of problems. First, constant exposure to the elements can cause the wood to deteriorate over time. In order to prevent (or delay) this from happening, the wood must be treated with a wood preservative. Treating the wood can be a time consuming and messy process. In addition, wood is frequently stained or painted to achieve a desired color, but the color can fade, chip, and peel over time.
In addition, the dimensions of wood vary depending on the moisture content of the wood and the temperature. These variations can cause warping of the boards which can cause the surface of the deck to become uneven over time. Finally, when a tongue and groove arrangement of boards is used, if the head of the nail is not flush with the surface of the board, the next board will not fit against it properly, resulting in an uneven surface.
Synthetic wood compositions have been advanced as a substitute for natural wood. Synthetic wood compositions may offer improved durability and enhanced moisture resistance over natural wood. Nevertheless, synthetic wood compositions may still expand and contract as a result of temperature and moisture variations. Consequently, a deck made from synthetic wood deck planks may also become uneven due to expansion and contraction of the synthetic wood material.
Therefore, it is desirable to have a method of making an improved tongue and groove joint. It is also desirable to have a method of making a sacrificial limb for a deck plank so that the deck plank has improved dimensional stability and decreased maintenance. The method preferably ensures that the deck will remain smooth and even after it is installed. In particular, the method preferably enables the tongue-and-groove joint between deck planks to compensate for expansion and contraction of the material of the deck planks.
The present invention satisfies some or all of these needs. The present invention provides a method of manufacturing a sacrificial limb for a deck plank. The sacrificial limb is preferably adapted to fracture, if necessary, in response to expansion of the material of the deck plank to limit vertical displacement of the top surface of the deck plank.
A preferred method of manufacturing a sacrificial limb of the present invention starts by providing a deck plank that is comprised of a wood replacement material. The deck plank has a tongue that is adapted to fit with a groove of an adjacent deck plank. The adjacent deck plank may be substantially similar to the provided deck plank. A channel is cut in the tongue of the provided deck plank. The channel is adapted to induce the tongue to fracture when expansion of the wood replacement material causes sufficient pressure between the tongue and the groove of the adjacent deck plank.
The deck plank may be provided by any appropriate means, e.g., extrusion or molding. In a preferred method, the channel is substantially straight, and it extends the entire length of the deck plank. The channel may be cut in any appropriate place on the tongue. For example, the channel may be cut in a bottom edge or a top edge of the tongue.
The tongue of the deck plank preferably includes a recess that divides the tongue into a first limb and a second limb. The deck plank may be provided with the recess. Alternatively, the method may further include cutting a recess in the tongue. The recess preferably extends in a plane that is substantially parallel to a top surface of the deck plank. In such embodiments, the channel may be cut in an edge of the tongue that defines the recess.
The deck plank may be made from wood, plastics, or from several other materials including conventional wood replacement materials such as synthetic wood compositions. However, it is believed that the present invention is unique apart from material considerations. The wood replacement material may be comprised of a polymer, such as homopolymers and copolymers of polyethylene, polyvinyl chloride, polypropylene and ABS, or a mixture of these polymers. The wood replacement material also preferably includes cellulose material for appearance, stiffness, and economics. The cellulose material may be in the form of fibers (e.g., wood flour and the like). Table 1 shows an example formulation of a wood replacement material. The deck planks made from wood replacement materials are preferably extruded using conventional plastics extrusion equipment and one or more dies to provide the desired cross section shape of each plank.
In addition to the novel features and advantages mentioned above, other objects and advantages of the present invention will be readily apparent from the following descriptions of the drawings and preferred embodiments.